This invention relates generally to exercise machines, and is particularly concerned with compound movement exercise machines which have a pivoting user support.
There are two basic types of exercise movements, isolation and compound. Isolation movements are designed to isolate a specific muscle or muscle group and to reduce body part movement to involve rotation of a single joint. Leg extensions and biceps curls are examples of isolation movements. Compound movement exercises involve more than one body part and require multiple joint action. Because of this, they exercise a greater number of muscles/muscle groups. There is also a difference in the travel path for the two types of movement. Isolation movements tend to be rotational with concentric travel paths, while compound movements tend to be curvilinear, with elliptical travel paths.
Compound movements are a natural and fundamental form of exercise and show up in everything from professional athletics to everyday activities. Jumping, rowing, swimming, and throwing all involve multi-joint movements. Squats, bench presses, chin-ups, bar dips, shoulder presses, and the like, are all compound movement exercises. While fundamental in everyday life, they can be difficult for many people to perform as exercises, requiring balance and coordination as well as strength to follow the proper movement path. Improper form by the exerciser can make the exercise more difficult, increase stress on the joints, and even lead to possible injury.
Various exercise machines have been developed for performing compound movement exercises involving various muscles and muscle groups. Some of these have a stationary user support, while others have a pivoting or movable user support, which may or may not be linked to the exercise arm or user engagement means. One problem in most or all prior art designs is the unnatural and exaggerated arcing movement found in pivoting arm exercise machines, which do not accurately simulate the natural body movement found in free weight and/or free bar exercises.
Movable user supports linked to the movement of an exercise arm are extremely common in exercise machines, and are generally known as composite motion exercise machines. U.S. Pat. No. 2,252,156 of Bell and U.S. Pat. No. 6,251,047 of Stearns show bicycle and exercise bike designs in which a seat or user support is linked to an exercise arm or crank and pedal system to provide up and down movement to the seat. The most common application of movable user supports is found in rowing and horse riding type exercise machines, which use the weight of the user as the exercise resistance. In U.S. Pat. No. 3,446,503 of Lawton, U.S. Pat. No. 4,743,010 of Geraci, and U.S. Pat. No. 5,342,269 of Huang, a seat and exercise arm are pivotally mounted on the base frame, with the seat linked to the exercise arm for dependent movement. U.S. Pat. No. 4,300,760 of Bobroff, U.S. Pat. No. 5,299,997 of Chen, U.S. Pat. No. 5,356,357 of Wang, U.S. Pat. No. 5,453,066 of Richter, U.S. Pat. No. 5,458,553 of Wu, U.S. Pat. No. 5,503,608 of Chang and U.S. Pat. No. 5,507,710 of Chen all show horse riding type exercise machines. They all consist of a user support pivotally attached to a base frame, and one or more exercise arms pivotally connected to the frame and pivotally linked to the user support.
U.S. Pat. No. 6,264,588 of Ellis shows a composite motion movement machine that has a moving exercise arm linked to a movable user support, and a pivoting truck system which is slidably connected to rails mounted both on the main frame and user support. The movable user support and exercise arm are both pivoted at the same point on the base frame, in front of the user support. A belt connects the exercise arm to the truck. When the exercise arm is pushed or pulled, the belt pulls the truck along the rails, forcing the user support to rotate about its pivotal connection to the frame. This design puts all of the user's weight on one side of the pivot, producing a high initial lifting resistance when the user starts the exercise, and also has no means for properly aligning the exercise arm and user support during the exercise movement.
Movable seats linked to exercise arms have also been used in multi-purpose exercise machines, such as U.S. Pat. No. 5,330,405 of Habing, U.S. Pat. No. 5,334,120 of Rasmussen, U.S. Pat. No. 5,669,865 of Gordon, U.S. Pat. No. 5,733,232 of Hsu, and U.S. Pat. No. 6,244,995 of Prsala. In U.S. Pat. No. 5,330,405 of Habing, a lever arm is pivotally connected to the base frame and supports a movable sub-frame including a user support which is also pivotally connected to the stationary base frame. An exercise arm is pivotally mounted on the sub-frame and linked to the lever arm via cables and pulleys, so that movement of the exercise arm pulls the cables lifting the lever arm, and causing the sub-frame to pivot about its connection to the base frame and rise against the weight of the user. U.S. Pat. No. 5,733,232 of Hsu shows another multi-purpose exercise machine with a pivoting seat, but in this case the back pad is stationary and only the seat pad is pivoted. Thus, the seat travels in an arcuate path without any secondary stabilization for the user, forcing the user to try to maintain their balance on the seat as it arcs upward. Also, in this design, the pivot point for the seat is located at a spacing behind the user position, so that all of the user's weight will oppose the user when starting an exercise from rest. Neither of these machines has any capability for aligning the user and user support with a rigid exercise arm, and thus do not maintain or support the user in the proper position throughout the exercise.
Gordon shows a multi-purpose exercise machine that has a hinged, two-piece user support that folds and unfolds with each exercise repetition. The user support consists of a seat portion and a backrest portion, which are pivotally connected together. The user support is pivotally connected to a main frame, as is a first exercise arm. This first exercise arm provides pressing and pulldown exercises. A second exercise arm is pivotally connected to the user support for providing leg exercises. This second arm travels with the seat portion of the user support. A connecting link pivotally connects the first exercise arm with the user support so that movement in the arm forces movement in the user support. The link connects to the user support at the same pivot that joins the seat portion with the backrest portion. In a second embodiment a flexible line connects the user support with the main frame and has user-engaging handles attached to one end so that movement to the handles results in movement to the user support. In this design, the flexible line acts as both connecting link and exercise arm. In both designs, the seat and backrest do not travel in a fixed relationship to each other and additional support such a footrest, safety belts and thigh gripping surfaces are required to keep the user properly and safely positioned in the user support. Because most of the combined weight of the user and user support remain on one side of the user support's gravitational centerline, this weight is used as partial exercise resistance. Movement of the user support is designed to be an exercise of its own, rather than providing proper positioning/alignment of the user relative to the exercise arm. The folding and unfolding of the two-piece user support constantly works the abdominal and low back muscles, which means that these muscles are being worked even when other exercises are being performed. The user cannot truly isolate any one specific muscle or muscle group. The stomach cannot be worked without working the low back, the arms, chest, shoulders, upper back and legs all must be worked with one another or at the least with both the stomach and low back. Because of this the user cannot fully fatigue other muscles as the abdominals and low back would fatigue first.
A squat exercise apparatus is described in both U.S. Pat. No. 5,108,095 of Nichols and U.S. Pat. No. 5,603,678 of Wilson. In Nichols, a four bar linkage system is used to keep the user support (back pad and shoulder pads) vertical while it is being moved along an arcuate exercise path. This design requires a belt around the user's waist to keep them in the proper position, and is awkward to use. The entire weight of the moving carriage is positioned on one side of the pivotal connection to the main frame, creating an initial starting weight or resistance which may be too heavy for most users, and requires addition of a counter balance to offset the carriage weight. This in turn poses a hazard to anyone standing next to, or walking past, the moving part. Wilson has a generally T-shaped user support frame rotatably mounted on the base of the stationary frame. A back pad, handgrips, and resistance receiving means are all attached to the pivoting user support frame. The user pushes against a fixed foot plate in order to pivot the backrest. There is no secondary user support to properly position the user, and improper positioning could result in serious injury.
Various exercise machines are also known which allow users to perform chin up and/or bar dip exercises. Some examples of these machines are described in U.S. Pat. No. 3,592,465 of Fulkerson, U.S. Pat. No. 3,707,285 of Martin, U.S. Pat. No. 4,111,414 of Roberts, U.S. Pat. No. 5,011,139 of Towley, U.S. Pat. No. 5,322,489 of Webb, U.S. Pat. No. 5,449,959 of Holmes, and U.S. Pat. No. 5,540,639 of Potts. In these machines, the user sits or stands on a movable user support, and pushes or pulls with their hands in order to raise their body, assisted by the counter-balanced user support. While the user support moves in these designs, it is not urged to do so by movement of an exercise arm. The only user engaging means or handles are stationary and fixed to the main frame. A further disadvantage of these machines is the limitation of the handle or user gripping position, which may put the hand and/or wrist of the user in an uncomfortable position at some point in the movement, causing undue strain which may lead to injury. U.S. Pat. No. 248,121 of Tuttle and U.S. Pat. No. 5,876,095 of Johnston describe exercise machines for performing dips in which a movable user support or platform is linked to an exercise arm, so that movement of the exercise arm forces movement of the user support. Both of these designs have the user support traveling upward in a generally vertical direction while the user support remains horizontal, and both place the exerciser's wrist in an awkward starting position. Neither of these designs describes or suggests orienting or aligning the position of the user support to the position of the exercise arm or user engaging means.
Current exercise machines for performing compound or multi-joint exercises, whether using composite motion or a fixed user support, do not accurately maintain proper positioning of the user throughout the exercise motion, can result in awkward hand or wrist positions, and often involve exaggerated and unnatural arcing movements, or linear, non-arcing arm movements, rather than the smaller elliptical movement associated with free weight or natural exercise movements. There is no provision for proper positioning of the user relative to the position of the user engaging portion of the exercise arm throughout the entire exercise motion. Often, an awkward starting or finishing position is required, causing strain and potential injury.